The CAT-ASVAB is a computer-based exam that is only provided at Military Entrance Processing Stations (MEPS) for enlistment purposes. The test is customized based on the taker’s answers, so if one question is answered correctly, the next one will be more difficult. This exam is timed, although users have the option of pacing themselves throughout the exam. However, it is not possible to go back through the test and check answers or change responses after they have been submitted. The CAT-ASVAB is broken down into 10 subparts, including basics such as arithmetic and verbal skills as well as auto information, electronics, shop, and mechanical knowledge.
You are tested in four critical areas — Arithmetic Reasoning, Word Knowledge, Paragraph Comprehension and Mathematics Knowledge (see below) — these scores count towards your Armed Forces Qualifying Test (AFQT) score. The AFQT score determines whether you’re qualified to enlist in the U.S. military. Your scores in the other areas of the ASVAB determine how qualified you are for certain military specialties. Score high, and your chances of getting the specialty/job you want increase. The better score you get, the better chance you have of pursuing the specialty or field that you desire.
To coordinate military strategy with political affairs, the President has a National Security Council headed by the National Security Advisor. The collective body has only advisory power to the President, but several of the members who statutorily comprise the council (the Secretary of State, the Secretary of Energy and the Secretary of Defense) possess executive authority over their own departments.
As of 2017, the U.S. spends about US$610 billion annually to fund its military forces and Overseas Contingency Operations. Put together, the U.S. constitutes roughly 40 percent of the world's military expenditures. The U.S. Armed Forces has significant capabilities in both defense and power projection due to its large budget, resulting in advanced and powerful technologies which enables a widespread deployment of the force around the world, including around 800 military bases outside the United States. The U.S. Air Force is the world's largest air force, the U.S. Navy is the world's largest navy by tonnage, and the U.S. Navy and the U.S. Marine Corps combined are the world's second largest air arm. In terms of size, the U.S. Coast Guard is the world's 12th largest naval force. 
The United States has the world's largest military budget. In the fiscal year 2016, $580.3 billion in funding were enacted for the DoD and for "Overseas Contingency Operations" in the War on Terrorism. Outside of direct DoD spending, the United States spends another $218 to $262 billion each year on other defense-related programs, such as Veterans Affairs, Homeland Security, nuclear weapons maintenance and DoD.
All of the branches work together during operations and joint missions in Unified Combatant Commands, under the authority of the Secretary of Defense with the typical exception of the Coast Guard. Each of the Unified Combatant Commands is headed by a Combatant Commander, a senior commissioned officer who exercises supreme command authority per 10 U.S.C. § 164 over all of the forces, regardless of branch, within his geographical or functional command. By statute, the chain of command flows from the President to the Secretary of Defense to each of the Combatant Commanders. In practice, the Chairman of the Joint Chiefs of Staff often acts as an intermediary between the Secretary of Defense and the Combatant Commanders.
Disclaimer: This is a private website that is NOT affiliated with the U.S. government, U.S. Armed Forces or Department of Veteran Affairs. U.S. government agencies have not reviewed this information. This site contains information about GI Bill benefits, VA loans, news and services for military veterans and is not connected with any government agency. GI Bill® is a registered trademark of the U.S. Department of Veterans Affairs (VA). If you would like to find more information about benefits offered by Veteran Affairs, visit the official site for veterans benefits at Veterans Affairs. The appearance of U.S. Department of Defense (DoD) visual information does not imply or constitute DoD endorsement.